I'm having the same issue. This quest is beyond overpowered. I was level 7 with 6 characters when I started this quest. The quest says it is at or below my level. Yet in the second area you encounter 2 mages, 1 priest, 1 champion, and at 3 least fighters. Every single one of them are 3 red skulls. Only 1 is active when you enter the room but they all immediately activate when you're spotted so you cannot sneak past. After that you have a couple of rounds at most before they wipe out your entire party.
I had all my characters pound on the mage, I had set down 3 traps before hand, set up a healing aura and set flame wall and every single enemy walked right through it with not even a hint of damage. By round 3 all but 2 of my characters were dead and the mage was still at least at 1/3 health.
How is this quest remotely at or below a 7th level party??
TBH I see the same problem with other quests as well. It's like the "difficulty" is some made up value while the enemies scale. I had to forego the "Family Pride" quest which is also at or below my level because I'm in a situation where I cannot complete it without a fight because I failed to do X at some arbitrary time earlier in the quest and now a fight is inevitable. Yet every enemy there is red skulls.